Power supply system and IV curve scanning method for power supply system

A current-voltage (IV) curve scanning method for a power supply system, wherein the power supply system comprises at least two inverters, each of the at least two inverters is configured to connect to at least one photovoltaic string, and the at least two inverters comprise a first inverter and a second inverter;

• and
• the method comprises:
• starting, by the first inverter at an IV curve scanning start time of the first inverter, to perform IV curve scanning on at least one photovoltaic string connected to the first inverter, wherein the IV curve scanning start time of the first inverter is determined based on a moment at which a first IV curve scanning instruction is received and a delay duration of the first inverter;
• and
• starting, by the second inverter at an IV curve scanning start time of the second inverter, to perform IV curve scanning on at least one photovoltaic string connected to the second inverter, wherein the IV curve scanning start time of the second inverter is determined based on a moment at which a second IV curve scanning instruction is received and a delay duration of the second inverter, and the IV curve scanning start time of the first inverter and the IV curve scanning start time of the second inverter are different, and a time interval between the IV curve scanning start time of the first inverter and the IV curve scanning start time of the second inverter is less than a preset IV curve scanning period;
• wherein the delay duration of the first inverter is T/N* (n1−1), and the delay duration of the second inverter is T/N* (n2−1), wherein T is the preset IV curve scanning period, N is the quantity of the at least two inverters, n1 is ranking of the first inverter in the at least two inverters, and n2 is ranking of the second inverter in the at least two inverters.

A power supply system, comprising:

• a system control unit and at least two inverters that establish a communication connection to the system control unit, each of the at least two inverters is configured to connect to at least one photovoltaic string, and the at least two inverters comprise a first inverter and a second inverter;
• the system control unit is configured to:
• send a first current-voltage (IV) curve scanning instruction to the first inverter, and send a second IV curve scanning instruction to the second inverter;
• the first inverter is configured to start, at an IV curve scanning start time of the first inverter, to perform IV curve scanning on at least one photovoltaic string connected to the first inverter, wherein the IV curve scanning start time of the first inverter is determined based on a moment at which the first IV curve scanning instruction is received and a delay duration of the first inverter;
• and
• the second inverter is configured to start, at an IV curve scanning start time of the second inverter, to perform IV curve scanning on at least one photovoltaic string connected to the second inverter, wherein the IV curve scanning start time of the second inverter is determined based on a moment at which the second IV curve scanning instruction is received and a delay duration of the second inverter, and the IV curve scanning start time of the first inverter and the IV curve scanning start time of the second inverter are different, and a time interval between the IV curve scanning start time of the first inverter and the IV curve scanning start time of the second inverter is less than a preset IV curve scanning period;
• wherein the delay duration of the first inverter is T/N* (n1−1), and the delay duration of the second inverter is T/N* (n2−1), wherein T is the preset IV curve scanning period, N is the quantity of the at least two inverters, n1 is ranking of the first inverter in the at least two inverters, and n2 is ranking of the second inverter in the at least two inverters.